I. Field of the Invention
This invention relates generally to apparatus for stabilizing a two-legged ladder, such as an extension ladder, against tipping and sliding, and more particularly to a leg assembly attachable to the side rails of such a ladder and which, when deployed, provide a substantially wider base for same.
II. Discussion of the Prior Art
There are basically two styles of ladder presently in use, the two-legged extension ladder and the step ladder. The extension ladder generally comprises two or more sections which are coupled to one another to permit one to slide vertically relative to the other. This style of ladder has its base or lower end resting on a ground surface and its upper end leaning against a stationary object such as a wall or a roof eave. A step ladder, on the other hand, generally has four legs, two being arranged in a front leg frame supporting steps or rungs and two back legs joined as a frame which is hinged, usually to a top step, to form a A-frame. Having four spaced-apart feet, a step ladder need not be leaned against a wall and is generally free-standing.
In the case of an extension ladder, extreme care must be exercised when positioning it so that a person mounting the ladder does not create a force vector tending to cause the feet of the ladder to slide to the rear, i.e., away from the wall, with the upper end of the ladder sliding down the wall. This can usually be prevented by properly setting the angle that the ladder is tilted so that the major force vector caused by the load is primarily directly downward.
An extension ladder is also subject to lateral tipping, especially when the user is stretching out to the side more than he or she should to perform work. That is, rather than getting off the ladder and moving it, users often lean laterally outward from the side of the ladder and this can cause an over-balancing to the point where the ladder may tip over sideways. This problem is compounded further when the ladder's feet are not resting on a planar, horizontal surface. Where the terrain is uneven or soft, there is a tendency for the ladder to lean or shift to one side, thus making it easier to tip when the climber leans to that one side.
There is disclosed in the prior art the use of telescoping stabilizing legs fastened to the upper portion of a step ladder and laterally deployable at the lower end relative to the base of the step ladder. Such stabilizers are effective to limit over-balancing and tipping of such a ladder. Examples of such prior art stabilizing legs are depicted in the Wojtowicz U.S. Pat. No. 2,997,127, the McBride U.S. Pat. No. 3,878,9I7, the Beach U.S. Pat. No. 4,433,754 and the Grebausky U.S. Pat. No. 3,901,354.
To applicant's knowledge, no one has yet invented an effective stabilizing system for a two-legged extension-type ladder. While the Leiser U.S. Pat. No. 2,149,781 depicts an attachment designed for use with ladders to provide bracing of the ladder against lateral movement, it is not particularly effective because of the point at which the stabilizing legs are attached to the ladder rails. Moreover, the mechanism used to join the stabilizing legs to the rails is difficult to use in practice and does not afford convenient stowage of the stabilizing legs when the ladder is not in use.
Accordingly, it is a principal object of the present invention to provide an improved ladder stabilizer kit which may readily be connected to an extension-type ladder for rendering it safer to use.
Another object of the invention is to provide an extension ladder having a pair of telescoping tubular extensible legs hingedly joined to the side rails of the ladder at a location near the top of the lowermost ladder section where the stabilizing legs may be swung out laterally and forwardly relative to the ladder's feet.
A still further object of the invention is to provide safety equipment for an extension-type ladder for rendering that ladder more stable against either slipping out from the wall at its base or tipping laterally about one ladder leg.